The Central American forms of the musician wren, Cyphorhinus lawrencii Lawrence

AMERICAN MUSEUM NOVITATES

Published by

Tue American Museum or Naturat History
Number 573 Mvenr ov Na Oct. 11, 1932

59.88,1 C (728)

THE CENTRAL AMERICAN FORMS OF THE MUSICIAN WREN,
CYPHORHINUS LAWRENCII LAWRENCE

By Joun T. Zrmmer

A short time ago, I was asked by Dr. C. E. Hellmayr to make com-
parisons of certain specimens of Cyphorhinus in this country for use in his
forthcoming discussion of the American Troglodytidae. A critical ex-
amination of the cotypes of C. I. lawrencit, made in this connection,
has led to the belief that a rearrangement of the Central American mem-
bers of the group is necessary. Through the kindness of Mr. Todd, of
the Carnegie Museum, Pittsburgh, Mr. Peters, of the Museum of Com-
parative Zoélogy, Cambridge, and Dr. Friedmann, of the U. S. National
Museum, Washington, I have been able to supplement the series of
specimens already at hand in this museum and to give a more compre-
hensive review of the situation than would, otherwise, have been possible.
Many thanks are hereby expressed for this generous assistance.

Starting first with lawrencii, itself, it is apparent that Lawrence had
at least three specimens, all from Lion Hill, Panam4 (=Canal Zone).
Two of these are marked as ‘‘type”’ on the labels but the third (a
partially albinistic specimen) bears no such designation though it is
mentioned by Lawrence in the original description (Ann. Lyc. Nat. Hist.
N. Y., VIII, p. 5, 1863). In the absence of a single specimen alone desig-
nated as type, all three of Lawrence’s original specimens should be taken
as cotypes.

In addition to these three skins, I have examined five more from the
Canal Zone (including three from Loma del Leén or Lion Hill) and one
from La Chorrera, just west of the Pacific end of the Canal Zone. These
birds all unquestionably represent true lawrencii. Nineteen skins
from the extreme eastern end of Panama are not distinguishable from the
Canal Zone birds and must also be referred to lawrencit. Eight ex-
amples from Saotata, Rio Atrato, Colombia, topotypes of C. 1. assimilis,
also seem to be inseparable from lawrencit.

Some of the skins from Saotata are a little paler brown on the upper
surface than Canal Zone and eastern Panamé birds, with a very slight
olivaceous tone, but at least one Saotata example is darker than the

2 AMERICAN MUSEUM NOVITATES [No. 573

Canal Zone specimens. Lawrence’s male cotype has the belly no paler
than the breast but both female cotypes have the abdomen noticeably
paler, grayish white in one, more buffy in the other. They can be matched
by some of the Saotata specimens. Another topotypical female and the
male from La Chorrera have the same character and even certain Costa
Rican examples, of which more will be said later, show the belly distinctly
whitish. The characters of assimilis, therefore, appear to be shared with
lawrenci though perhaps they may be more constant in the region of the
lower Rio Atrato.

If assimilis is to be recognized as distinct, it must have a very re-
stricted range at the mouth of the Rio Atrato in northwestern Colombia.
Farther up the Atrato, at Alto Bonito, the resident form unquestionably
is C. l. phaeocephalus as already recorded by Chapman (Bull. Amer. Mus.
Nat. Hist., XXXVI, p. 527, 1917), and the skins from the adjacent por-
tion of eastern Panamé are lawrencii. It seems more probable that
assimilis represents the most extreme elements of lawrencii, though un-
fortunately it is antedated by Lawrence’s form.

It may be of interest to note that one of Lawrence’s females has the
entire throat white in a broad gular patch as described by Lawrence
himself, while a male from the Rio Sambi and another male from Tacar-
cuna, eastern Panam4, have the same characteristic. Numerous skins
show traces of white or whitish at the bases of some of the feathers of the
throat and sides, and a male from El Real, eastern Panamé, has one or
two white feathers on the upper throat. Albinism in this form apparently
has a tendency to concentrate somewhat frequently in the gular region.
Incidentally, the tone of rufous in the throat and breast is extremely
variable without any geographical significance.

Four skins from Nicaragua and one from British Honduras are very
like the Canal Zone birds though they show some very slight differences.
There is possibly a faintly greater tinge of rufescence in the brown of the
lower flanks and the rump in the Nicaraguan and Honduran examples;
the bars on the wings and tail are a little less sharp and clear; the malar
region has the blackish area adjoining the base of the bill averaging
smaller; the belly does not reach the extreme of paleness that is found in
lawrencii; the bars on the lesser upper wing-coverts are sometimes
obsolete, though sometimes well developed. These differences are not
striking and would hardly be sufficient for the recognition of a distinct
form if the range were continuous with that of lawrencii, but the Carib-
bean slopes of Costa Rica are inhabited by a very different subspecies,
completely separating Nicaragua and Honduras from the country in-

1932] . CENTRAL AMERICAN MUSICIAN WRENS 3

habited by lawrencit. It is necessary, therefore, to resurrect the name
“richardsoni,’”’ applied by Salvin (Bull. Brit. Orn. Club, VI, p. xxxii,
1893) to Nicaraguan examples. More material from Nicaragua and
British Honduras may show characters additional to those I have men-
tioned.

Fourteen Costa Rican birds are decidedly darker than the series of
lawrencit and richardsoni, and a single skin from Almirante, western
Panama, agrees with the Costa Rican examples. So constant is the
difference that it is advisable to name a new form from this region.
Accordingly it may be known as follows.

‘Cyphorhinus lawrencii infuscatus, new subspecies

Tyrer from Carrillo, Costa Rica, altitude 1000 feet. American Museum of
Natural History, Dwight Collection No. 57,595. moult male collected April 25,
1924, by Austin Smith.

Draqnosts.—Darker than either C. 1. lawrenciit or richardsoni; forehead and
crown often distinctly blackish; abdomen less distinctly whitish than in most
lawrencii; malar region with reduced amount of blackish as in richardsoni.

Ranese.—Caribbean lowlands of Costa Rica and western Panans‘.

DESCRIPTION oF Typr.—Forehead and crown blackish; hinder part of head,
neck, and mantle Mummy Brown x Prout’s Brown’; rump Prout’s Brown x Mars
Brown; upper tail-coverts a little brighter on the margins. Lores blackish at the
tips of the feathers, dark rufous at the base; a small area in the malar region at the
base of the bill dusky; remainder of the sides of the head, including a stripe over the
auriculars Chestnut x Sanford’s Brown, the color continued over the chin, throat, and
upper breast; sides of neck and sides of breast a little paler than the mantle, continuous
in color with the upper flanks; lower flanks deepening to Argus Brown x Brussels
Brown; lower breast and belly Buffy Brown, with slightly paler margins which are
somewhat tawny on the lower breast; under tail-coverts margined broadly with deep
Sanford’s Brown x Burnt Sienna. Feathers of occiput, nape, mantle, sides of neck,
and sides of breast with broad white bases. Wings externally somewhat brighter and
slightly more rufescent than the back, strongly barred with narrow blackish lines
which are continued more narrowly and less prominently on the upper wing-coverts,
becoming subobsolete on the lesser series; under wing-coverts and axillars Pinkish
Cinnamon; inner margins of remiges Vinaceous Buff. Tail dark Mars Brown x
Prout’s Brown above, paler on the under side, barred like the outer margins of the
remiges with black. Bill black (in dried skin); lower margin of mandible somewhat
paler; feet dark brown. Wing, 68 mm.; tail, 31; exposed culmen, 19; culmen from
base, 22; tarsus, 24.

Remarks.—An occasional skin from Costa Rica is lighter than the
others, approaching the darkest lawrencii, but there is no actual over-

1Names of colors when capitalized pee direct comparison with Ridgway" s ‘Color Standards
and Color Nomenclature.’

4 AMERICAN MUSEUM NOVITATES [No. 573

lapping. When the birds are laid out in series the difference is quite
pronounced.

The color of the throat is too variable in each form to be of any
assistance. The color of the malar region is more useful though it varies
also. The Costa Rican birds have an occasional touch of blackish ad-
jacent to the base of the bill (as in the type of infuscatus) but many
skins lack it completely and have this region uniform with the throat.
On the other hand, lawrenczi usually has a distinct blackish patch in that
position, sometimes extensive and rarely absent. Both series occasionally
have the lores rufescent, and sometimes have the rufous color extended
over the eye in a superciliary stripe. This is of more frequent occurrence
in lawrencit where, also, the forehead is sometimes noticeably tinged with
rufous. One topotype of ‘‘assimilis” has the whole forehead strongly
pale rufous, suggesting the pattern of the modulator group. Most skins of
lawrencii have the rump hardly brighter than the mantle while infuscatus
has it somewhat warmer, though the rufescence is masked by the general
blackish tone of the entire upper surface. The occasional whitish tint
of the belly has already been mentioned.

The name Cyphorhinus (Cabanis, 1844) long applied to this genus,
was dropped by Richmond (Auk, XIX, p. 92, 1902) because of an earlier
Cyphorhina (Lesson, 1843), and Leucolepis (Reichenbach, 1850) was used
as the next available name. Under the ‘International Rules of Zoological
Nomenclature,’ Cyphorhina does not disqualify Cyphorhinus which
should be reinstated as the earliest name for the genus. ae
SPECIMENS EXAMINED

C. 1. lawrencit.—PanamA: (Lion Hill), 1 o& (cotype), 2 9 (cotypes); Loma del
Leén (Lion Hill), 2 #,1 9'; Gatun, 1 #; Barro Colorado Island, 1 9; La Chor-
rera, 1 oc; Tacarcuna, 5 3,4 9; Capeti, Darien, 1 (?); Tapalisa, 1 @; Chepigana,
‘1 (?); El Real, Rio Tuyra, 2 #7, 2 9,1 (?); Rfo Sambi, 1 #, 1 9. CoLomBia:
Saotata, Rio Atrato, 4 7,3 97,1 (?).? |

C. 1. richardsoni.—Nicaraaua: Los Sébalos, 2 7,1 9,1 9%. British Honpuras:
Segovia River, 1 9.

C. 1. infuscatus.—Costa Rica: Atirro, 1 9; Carrillo, 3 7,2 9; Parismina, 2 <,
2 9: Guacimo, 1,1 9; Guapiles, 1,1 9. PanamA: Almirante, Boca del Toro,
1 of.

C. 1. phaeocephalus.—Cotomsia: Alto Bonito, 3 7; Baudo, 1 o’,2 9; Barbacoas
1 @; Puerto Valdivia, 1 ¢. Ecuapor: Esmeraldas, 4 3, 2 9; Rio de Oro, 1 9,
1 (?); Cerro Manglar Alto, 1 @; Chimbo, 1 o7,1 9; La Chonta,1 97,1 9.

1§pecimens in Museum of Comparative Zodlogy, Cambridge.
*8pecimens in Carnegie Museum, Pittsburgh.
38pecimen in U.S. National Museum, Washington.